Zika Virus Update: Disease Linked To More Neurological Conditions

Experts have declared that the Zika virus is causing microcephaly and Guillain-Barré syndrome. Now, some researchers believe that the virus, which is transmitted by the Aedes aegypti mosquito, also causes other neurological disorders.

The Americas have seen an outbreak of Zika these past few months. Last week, the World Health Organization declared that Zika causes microcephaly and Guillain-Barré based on an increasing number of preliminary research.

Other Infections Caused By Zika Virus

Recent case reports, however, claimed that people who got infected by Zika also developed other neurological infections on the brain and spinal cord, aside from the abovementioned conditions. Among these cases is a 15-year-old girl in Guadeloupe who was diagnosed with acute myelitis (an inflammation of the spinal cord).

There is also a case study in France of a man who developed meningoencephalitis (inflammation of the brain and its outer membranes), both reported by the Atlantic. A new research in Recife, Brazil has discovered two people with acute disseminated encephalomyelitis, or ADEM as well.

Acute Disseminated Encephalomyelitis

The National Institutes of Health described ADEM as a "brief but widespread attack of inflammation in the brain and spinal cord," the Atlantic reported. Medscape wrote that ADEM "bears a striking clinical and pathological resemblance to other acute demyelinating syndromes (ADS) of childhood, including multiple sclerosis (MS)."

The research from Recife found six patients who displayed neurological symptoms (post-flavivirus symptoms), which are the two ADEM cases and four Guillain-Barré cases. Five of the patients in the study had "sustained motor dysfunction" after getting discharged, while one of them got vision problems and one with cognitive decline.

Both ADEM and Guillain-Barré, however, are commonly temporary conditions, the Atlantic noted. ADEM, myelitis, and Guillain-Barré can harm myelin, the protective sheath around nerve fibers. A damaged myelin can result to long-term repercussions for nerve function.

Nerve Cells Targeted

Those recent studies led researchers to believe that the Zika virus particularly targets nerve cells, but they are still unsure whether these neurological complications were always in association with Zika or if they're new. A study -- published in the journal Cell Stem Cell -- found that Zika thrives in neural stem cells, which could be the reason why it causes microcephaly.

Scientists have given two reasons as for why those new complications are revealing themselves just now. The first is that, "as the virus is spreading through such large populations, it is revealing aspects of Zika that went unnoticed in earlier outbreaks in remote and sparsely populated areas," Reuters reported. "The second is that the newly detected disorders are more evidence that the virus has evolved."

Zika's effects on newborns are the primary focus, but ongoing research showed that the virus can be serious for older children and adults as well, even though the illness' effects are mostly mild amongst them, the Atlantic noted.